1. Field of Invention
This invention relates to the field of liquid purification and separation, and more specifically to purification using a regenerating ion exchange material.
2. Description of Related Art
Ammonia is a hazardous water pollutant due to its toxicity to aquatic ecosystems and its oxygen consumption during environmental degradation. Ammonia also promotes increase of phytoplankton in a water body, resulting in even greater oxygen consumption. In ammonia-polluted ecosystems, native aquatic species may die out from lack of oxygen. Furthermore, ammonia- and phytoplankton-polluted waters may be unsafe for human and animal consumption without extensive water treatment.
Ammonia is present in human, animal and industrial wastes in municipal and other wastewater processing systems. Removal of ammonia from wastewater is an energy-intensive process that has conventionally been achieved using microorganisms to convert ammonia to nitrite and then nitrate under aerobic conditions. This requires energy-intensive aeration to feed oxygen to the microorganisms, a process that is often performed in an activated sludge system during secondary wastewater treatment. Activated sludge processes generally represent nearly 50% of the energy consumption at a typical municipal wastewater treatment plant.
There is a strong interest in using anaerobic processes for wastewater treatment since they require no oxygen input. However, anaerobic systems do not degrade ammonia; rather they generate it. Current ion exchange processes are limited due to their inability to effectively dispose of ammonia-contaminated regeneration liquids. Thus, current wastewater treatment practice is still limited by energy-intensive aeration requirements to remove ammonia from wastewater.
There is an unmet need in the art for an anaerobic process for treating ammonia in wastewater.
There is a further unmet need for an energy-efficient process for treating ammonia in wastewater.